Effect Of Age On The Immunogenicity Of Yeast Recombinant Hepatitis B Vaccines Containing Surface Antigen (S) Or Pres2+S Antigens

A single-blind, multicenter, phase II trial of yeast recombinant hepatitis B virus (HBV) vaccines containing surface antigen (S) alone or with PreS2 (PreS2+S) was conducted in 282 healthy HBV-seronegative adults aged 20–59 years. Each volunteer was randomly assigned to receive HBV vaccine containing 10 µg of S or one of three doses of PreS2 plus S: 2 + 10 µg, 4 + 20 µg, or 8 + 40 µg. The level of antibody to HBV surface antigen reached depended on the dose of S, not PreS2, received. In each vaccine group, volunteers 20–39 years old had higher titers of anti-PreS2 and antibody to S than those 40–59 years old. The age-related effect on immune response to HBV vaccination suggests that adults should beimmunized against hepatitis Bat as early an age as possible and that older persons may need a higher dose or booster immunizations to achieve durable immunity.